def _create_boundaries(self, thickness):
"""Create boundary walls of given 'thickness'"""
width, height = self._pixel_size
walls = [
('top', (0 - thickness, 0 - thickness), (width + thickness, 0 - thickness)),
('bottom', (0 - thickness, height + thickness), (width + thickness, height + thickness)),
('left', (0 - thickness, 0 - thickness), (0 - thickness, height + thickness)),
('right', (width + thickness, 0 - thickness), (width + thickness, height + thickness)),
]
for wall_id, top_left, bottom_right in walls:
wall = BoundaryWall(wall_id, self._space.static_body,
top_left, bottom_right, thickness)
self._space.add(wall.get_shape())
def scroll(self):
"""Scroll the view along if the player is within SCROLL_RADIUS
from the edge of the screen.
"""
# calculate the x distance from the right edge
x_position = self._player.get_position()[0]
x_offset = self._view.get_offset()[0]
screen_size = self._master.winfo_width()
edge_distance = screen_size - (x_position + x_offset)
if edge_distance < SCROLL_RADIUS:
x_position -= 5
# place a backstop boundary wall on the left side of the screen
# to prevent the player from going backwards in the game
world_space = self._world.get_space()
wall = BoundaryWall("backstop", world_space.static_body,
(x_position, 0),
(x_position, self._world.get_pixel_size()[1]), 5)
world_space.add(wall.get_shape())
# shift the view offset by the screen size
self._view.shift((-(screen_size - SCROLL_RADIUS), 0))